Intravenously administered emulsion from a lecithin base and method of preparation

ABSTRACT

An emulsifier from lecithin base prepared by solvent extraction can be used for intravenous administration. The lecithin base is obtained by filtering or centrifuging, subjecting a solution of a starting lecithin which is soluble in alcohol, in a mixture of alcohol and water, with a defined alcohol:water ratio, to solvent fractionation. Glycerine and soya oil are added to form the emulsion.

This application is a continuation-in-part of pending Ser. No. 212,211filed by the applicants on Dec. 2, 1980, now U.S. Pat. No. 4,357,353.

The instant invention relates to a process for the preparation of anemulsifier from lecithin base by solvent extraction, and to theemulsifier from lecithin base obtained by such process, as well as theuse thereof in fat emulsions for intravenous administration.

Lecithins are phospholipid mixtures and present a group of naturalsubstances accompanying fats in a great variety of mixtures ofmolecularly defined individual lipids. Such phospholipids are widelyused as emulsifiers for different purposes, in particular in medicinesand foods.

While crude phospholid mixtures, e.g. crude lecithin of the soybeanwhich is obtained in great quantities when removing the mucilage fromsoybean oil as a partial step in refining the fat, are regarded as wasteproducts, fractionating the crude lecithin improves the value thereof,and the product may be used for different purposes, depending on itscomposition. The fractionation partly consists of enriching certaincomponents and partly of eliminating undesired secondary components.

Fractionating so far met with considerable technical difficultiesbecause of the great variety of components which have physicalproperties that are in part very different and in part very similar.

Attempts to separate or fractionate the substances contained in lecithinor in the phospholipid mixtures by virtue of their differentsolubilities in certain solvents practically did not meet with successso far since the individual lipides of the phospholipid complex greatlyinfluence one another in their solubility. It is known from U.S. Pat.No. 2,090,537 to produce hydrated lecithin from crude lecithin bysolvent fractionation. However, essentially this amounts to no more thana removal of fat, while the composition of the fractionated productstill is extremely complex. The hydrated form of the lecithin obtainedis not suitable for many applications, in particular in thepharmaceutical field.

Further fractionating is achieved by adsorptive fractionation of thephospholipid complex on adsorbents, such as Al₂ O₃, MgO, MgCO₃ andactivated carbon. What is obtained specifically is an enrichment ofphosphatidylcholine (Pc).

Methods of this kind are known from DT-AS No. 1 777 772 and 1 053 299and from the publication in J. Biol. Chem. 192 (1951), page 623.

A distinct disadvantage of these methods is the loss of adsorbates sincea quantitative desorption is not achieved, and thus also the renewed useof the expensive adsorbents at least restricted.

It is another disadvantage of the adsorption processes that there can beno separation of non-polar impurities. Among the non-polar impuritiesthere are, above all, the accompanying fats. As regards the proceduraltechnique, adsorption methods are characterized by the need forsubsequent fine filtration and this can be a very costly process step,especially in the production in connection with GMP. These industriallyexploited processes have the further disadvantage that they are suitablefor discontinuous operation only.

It is also known to fractionate phospholipid mixtures by chromatographicseparating methods with which, however, again different adsorbents mustbe used and with which different adsorption-desorption balances of thecomponents of the mixture are utilized for the fractionation. Althoughsemi- or fully continuous chromatographic separating processes havebecome known in this context, they can be applied only if a quantitativedesorption is achieved, which is not the case with the phospholipids forthe above mentioned reasons. Moreover, operation at greater rates offlow and in greater units is impossible especially with columnchromatography so that it is practically limited to the laboratoryscale.

It is the object of the invention to provide a process by whichphospholipid mixtures can be fractionated commercially, i.e. withoutgreat technical expenditure in continuous operation and with thesmallest possible number of process steps, recovering a product which issuitable as an emuslifier in fat emulsions for intravenousadminstration.

It was found that in accordance with the invention the desired productcan be obtained by filtering or centrifuging, subjecting a solution of acertain starting lecithin, which is soluble in alcohol, in a mixture ofalcohol and water, with a certain alcohol:water ratio, to solventfractionation.

Surprisingly, it was discovered that separation into different phases isobtained if a certain ratio between alcohol and water is observed in thesolvent mixture, i.e. within certain mixture limits in the solvent. Anda lecithin component which is not soluble in the solvent mixturementioned is separated as a finely disperse precipitate or as anemulsion. If the precipitate is formed, separation by gravity such ascentrifuging is possible, whereas in the case of the formation of anemulsion, the separation cannot be effected by gravity. In both cases,however, phase sepreparation by filtration is possible, in particular byultrafiltration. With emulsions this is the only possible separation.

The fractionation of phospholipid mixtures or lecithins by solventextraction according to the invention, as well as the separation thusmade possible of the resulting unsoluble phase by gravity or filtrationis surprising because the molecular weights of the main components ofthe lecithin lie within the same range as those of the accompanyingfats, namely approximately between 700 and 900, so that successfulfractionating of the principal components of lecithin by filtrationseemed to have no chance of success. True, it was known that lecithinand water form association complexes of different structure depending onthe chemical properties of the individual phospholipids, the molarcomposition of the lecithin, the concentration in the aqueous solution,and the temperature. Yet it could not be expected either thatfractionating lecithin by way of such association complexes would bepossible since the individual phospholipids of the lecithin jointly takepart in the structure of these complexes, a fact also demonstrated bytheir mutual influence on the solubility. For the above reasons the useof filtration, including ultrafiltration, has not been accepted so faror not been realizable with success for cleaning and fractionatingphospholipids.

In accordance with the invention the solvent extraction and separationof the desired product are made possible in a particularly simplemanner, the criterion being the adjustment of a certain ratio betweenalcohol and water in the solvent mixture consisting of these twocomponents.

A solution of a phospholipid mixture in alcohol is started fromaccording to the invention and water in certain quantities is added.

It was found that when adding water to an alcoholic solution of egglecithin in an amount of from 35 to 65%, based on the resulting solventmixture, immediate flocculation of an unsoluble phase takes place. Thisunsoluble phase can be isolated by centrifuging or filtering, e.g. byultrafiltration. It has also been discovered that the product thusobtained is so rich in phosphatidylcholine (Pc) and already contains asuitable ratio between phosphatidylcholine and phosphatidylethanolamine(Pe) that it is suitable as an emulsifier in fat emulsions intended forartificial feeding by intravenous administration.

According to another embodiment of the invention water in an amount offrom 5 to 65%, based on the resulting solvent mixture, is added to asolution of egg lecithin in alcohol. Also in this case a phaseseparation takes place. When adding water in an amount of from 5 to 35%,based on the resulting solvent mixture, a phase separation takes placeafter a long a period of rest, i.e. after about 12 hours, for exampleover night.

According to another embodiment of the invention water in an amount offrom 65 to 96%, based on the resulting solvent mixture, is added to analcoholic solution of soybean lecithin whereupon flocculation of theunsoluble phospholipid proportion takes place at once. This product canalso be separated easily by gravity, e.g. by centrifuging or byfiltration, such as ultrafiltration. The product also has the abovementioned desirable properties.

In accordance with yet another embodiment of the invention, water in anamount of from 5 to 55%, based on the resulting solvent mixture, isadded to an alcoholic solution of soybean lecithin. In this case thephase separation takes place after letting the mixture rest for about 12hours, e.g., over-night, whereupon the separation may be effected. Theresulting product likewise has the desired properties.

The further embodiments of the invention explained above aredemonstrated graphically in the table as shown in the drawing whichshows the fractioning egg lecithin and soybean lecithin, respectively,from a range of alcohol:water ratios.

Where phase separation takes place by the formation of an emulsion withsome embodiments of the invention, of course, the separation cannot beeffected by means of gravity, such as centrifuging. In this case,however, separation by filtration can be effected, and ultrafiltrationis provided in particular.

Equipment of conventional structure can be used for the ultrafiltration.Of the known structures, an ultrafiltration means of the flat membranemodule type is particularly preferred because, among others, it has theadvantage of permitting individual removal of the permeating substancefrom each membrane and thus convenient control of the membrane function.Moreover, a series connection of the membranes permits low repumpingrates. Celluloseacetate, polyacrylonitrile, polyamide, and polusulfonshave proved to be suitable membrane materials.

The following advantages are obtained when applying the ultrafiltrationfor separating the product to be prepared:

1. The arrangement is characterized by a high degree of efficiency.

2. The arrangement can be operated by process control, including acleaning cycle so that a considerable amount of time is saved incomparison with the adsorption process.

3. The arrangement can be built as a completely closed system so thatamong others it fulfills the requirements regarding sterility,regardless of the hygienic conditions of the working space.

4. The number of process step is smaller than in the case of anadsorption method.

5. The process conditions and thus the production properties arevariable within wide limits without requiring any apparatus measures.

6. The manufacturing costs are reduced since no adjuvants (apart fromthe solvent circulating in the process) are required, no product lossoccurs due to non-recoverable fractions, automatic plant control ispossible, and better quality of the product as well as better uniformityof the product quality are achieved.

The product obtained according to the invention either by centifuging orby filtering subsequently is dried in vacuum, excluding oxygen,preferably by way of freeze-drying. The product then obtained has amaximum fat content of 3%, preferably no more than 2%.

The product obtained by the method of the invention has the followingphysico-chemical parameters:

1. ratio between Pc and Pe from 7:3 to 6:1, preferably 4:1,

2. Pc content from 65 to 85% by weight, preferably from 75 to 80% byweight,

3. residual fat content less than 2%,

4. pyrogen-free in the rabbit test according to the EuropeanPharmacopoeia (1975) vol. 2, page 56 et seqq.,

5. clearly soluble in ethanol at 5% concentration,

6. clearly soluble in chloroform at 10% concentration,

7. maximum water content 2.5%, preferred maximum 1%,

8. maximum peroxide number 5, preferred maximum 1 (determined accordingto the DGF standard method F--I 3b (68).

The product (emulsifier) obtained by the process of the inventionfurther must fulfill the following conditions:

(a) The emulsifier must not be toxic.

(b) The emulsifier must be free of pyrogenic impurities.

(c) The emulsifier must permit the formation of a finely disperseemulsion having a shelf life of more than 2 years.

(d) The emulsifier must be adapted to be sterilized in the emulsion,i.e. it must be heatable to the sterilization temperature withoutdecomposing.

The requirements to be fulfilled by a product which is suitable forartificial feeding by intravenous administration are described in thebook "The Pathology of Parenteral Nutrition with Lipids" by SamuelWesley Thompson, published by Charles C. Thomas, Springfield, Ill.,U.S.A., cf. pages 14-16. It follows from this publication that extremelyhigh requirements must be fulfilled with respect to the purity and thespecific properties of such a product. This illustrates theextraordinary quality of the product obtained according to theinvention, which product is suitable as an emulsifier for fat emulsionsused for artificial nutrition and, therefore, meets the extremely highquality standards.

The invention will be explained in greater detail below with referenceto examples.

The percentages indicated in the examples for egg lecithin, soybeanlecithin, ethanol, and water each are based on the total weight of thestarting mixture.

EXAMPLE 1

0.45 kg (3%) of an egg lecithin fraction soluble in alcohol(phosphatidylcholine content=70%) were dissolved in 7.05 kg (47%) ofethanol.

7.50 kg (50%) of water were added to this solution to prepare thestarting mixture.

The starting mixture from which a precipitate flocculated at once wasmixed for 30 minutes at room temperature. The precipitate was separatedby centrifuging (3400 r.p.m.).

The centrifuged product was dried. The product obtained was suitable asan emulsifier for fat emulsions intended for artificial feeding byintravenous administration.

The product had a phosphatidylcholine content of 74%.

The mode of operation described could be carried out readily at roomtemperature (in a range from about 20° C. to 26° C.).

EXAMPLE 2

1.68 kg (8.4%) of an egg lecithin fraction soluble in alcohol weredissolved in 7.44 kg (37.2%) of ethanol, and 10.88 kg (54.4%) of waterwere added to constitute the starting mixture.

The resulting starting mixture was filled into an ultrafiltrationarrangement. After circulating the starting mixture for 30 minutes inthe arrangement the ultrafiltration was effected.

    ______________________________________                                        Test conditions:                                                              ______________________________________                                        module inlet pressure  5.6 bar                                                module outlet pressure 3.9 bar                                                flow of concentrate    4.7 m.sup.3 /h                                         flow of permeating substance                                                                         42 l/h                                                 separation limit of the membranes                                                                    25000 (MW)                                             test temperature       25° C.                                          duration of test       17 min.                                                ______________________________________                                    

In the test the permeating substance was collected separately and thuscontinuously withdrawn from the arrangement, while the retent circulatedin the arrangement. The retaining capacity of the module amounted to0.98. Upon termination of the test aliquot parts of the retent and ofthe permeating substance were reduced at 15 torr and 40° C. andsubsequently freeze-dried.

The retent thus obtained had an iodine number of 74.0 and aphosphatidylcholine content of 79.0%, whereas the permeating substancecontained only 10.9% of phosphatidylcholine. This shows that thefractionating test was successful.

EXAMPLE 3

The mode of operation was the same as in example 2. The starting mixturewas: 0.15 kg (0.80%) of an egg lecithin fraction soluble in alcohol,7.28 kg (39.0%) of ethanol, and 11.22 kg (60.2%) of water.

    ______________________________________                                        Test conditions:                                                              ______________________________________                                        module inlet pressure  6.4 bar                                                module outlet pressure 6.3 bar                                                flow of concentrate    1.6 m.sup.3 /h                                         flow of permeating substance                                                                         12.6 l/h                                               separation limit of the membrane                                                                     25000 (MW)                                             test temperature       20° C.                                          duration of test       57 min.                                                retention capacity of the module                                                                     0.91.                                                  ______________________________________                                    

The finishing was the same as with example 2, the entire retent beingisolated. The retent which was recovered as a yield of 41.8% (based onthe egg lecithin fraction used) had an iodine number of 72.0 and aphosphatidylcholine content of 76.5%, whereas the permeating substancecontained 13% of phosphatidylcholine. This demonstrates that thefractionating test was successful.

EXAMPLE 4

The mode of operation was the same as in example 2. The starting mixturewas: 0.62 kg (3.10%) of an egg lecithin fraction soluble in alcohol,9.54 kg (47.75%) of ethanol, and 9.82 kg (49.15%) of water.

    ______________________________________                                        Test conditions:                                                              ______________________________________                                        module inlet pressure  6.4 bar                                                module outlet pressure 6.2 bar                                                flow of concentrate    2.0 m.sup.3 /h                                         flow of permeating substance                                                                         33.6 l/h                                               separation limit of the membrane                                                                     25000 (MW)                                             test temperature       20° C.                                          duration of test       55 min.                                                retention capacity of the module                                                                     0.98.                                                  ______________________________________                                    

The finishing was the same as with example 3. The retent which wasrecovered as a 57.5% yield (based on the egg lecithin fraction used) hadan iodine number of 69.8 and a phosphatidylcholine content of 69.9%. Thefractionating test was successful.

EXAMPLE 5

The mode of operation was the same as with example 2. The startingmixture was: 0.24 kg (1.2%) of a soybean lecithin fraction soluble inalcohol, 4.62 kg (23.1%) of ethanol, and 15.14 kg (75.7%) of water.

    ______________________________________                                        Test conditions:                                                              ______________________________________                                        module inlet pressure  5.1 bar                                                module outlet pressure 4.8 bar                                                flow of concentrate    3.8 m.sup.3 /h                                         flow of permeating substance                                                                         21 l/h                                                 separation limit of the membrane                                                                     10000 (MW)                                             test temperature       22° C.                                          duration of test       15 min.                                                retention capacity of the module                                                                     0.92.                                                  ______________________________________                                    

The finishing was the same as with example 2. The retent recovered hadan iodine number of 99.8 and a phosphatidylcholine content of 70%. Ascompared to that the permeating substance recovered had an iodine numberof 51.2 and a phosphatidylcholine content of 20%. The fractionating testwas successful.

EXAMPLE 6

The mode of operation was the same as with example 2. The startingmixture was: 0.82 kg (4.1%) of a soybean lecithin fraction soluble inalcohol, 8.08 kg (40.4%) of ethanol, and 11.1 kg (55.5%) of water.

    ______________________________________                                        Test conditions:                                                              ______________________________________                                        module inlet pressure  6.8 bar                                                module outlet pressure 6.4 bar                                                flow of concentrate    2.0 m.sup.3 /l                                         flow of permeating substance                                                                         12.6 l/h                                               separation limit of the membrane                                                                     10000 (MW)                                             test temperature       22° C.                                          duration of test       30 min.                                                retention capacity of the module                                                                     0.92.                                                  ______________________________________                                    

The finishing was the same as with example 2. The retent recovered hadan iodine number of 103 and a phosphatidycholine content of 49.5%. Thefractionating test was only slightly successful.

EXAMPLE 7

Cleaning of lecithins, for example soybean lecithin and preparation ofpyrogen-free products.

Using the same mode of operation as with example 2 a total of 9 set-upsof 20 kg each were treated. The starting mixtures were: from 2 to 5% ofa soybean lecithin fraction soluble in alcohol, from 37 to 93% ofethanol, and from 4 to 35% of water.

    ______________________________________                                        Test conditions:                                                              ______________________________________                                        module inlet pressure  2.6 to 6.2 bar                                         module outlet pressure 1.6 to 5.4 bar                                         flow of concentrate    4.6 to 5.5 m.sup.3 /h                                  flow of permeating substance                                                                         51 to 199 l/h                                          separation limit of the membrane                                                                     25000 (MW)                                             test temperature       23 to 30° C.                                    retention capacity of the module                                                                     0 to 0.78.                                             ______________________________________                                    

A pyrogen-free product was obtained in each example.

EXAMPLES 8 to 22

Under the following conditions soybean lecithin was fractionated withthe aid of an ultrafiltration arrangement: Composition of the solutionto be fractionated: A maximum of 15% of a soybean lecithin fractionsoluble in alcohol, a maximum of 35% of ethanol or an aliphatic alcohol,and at least 60% of water (ultrafiltration).

Under the following conditions egg lecithin was fractionated with theaid of an ultrafiltration arrangement: Composition of the solution to befractionated:

A maximum of 15% of an egg lecithin fraction soluble in alcohol, amaximum of 52% of ethanol or an aliphatic alcohol, and at least 45% ofwater. Separation limit of the membranes: 25000 (MW).

Table 1 below lists the test conditions for treating other startingmixtures containing soybean or egg lecithin by means of ultrafiltrationand the results obtained.

                                      TABLE 1                                     __________________________________________________________________________    Test conditions and results of treating further soybean and egg               lecithin starting mixtures by ultrafiltration                                 __________________________________________________________________________                    starting mix-                                                                 ture composi-                                                                          test data of equipment                                               tion     used                                                 type of         lecithin                                                                           water                                                                             T  P. in                                                                            P. out                                                                            φP                                                                          KFl                                                                              PFl                                                                              retention                          Example                                                                            membrane                                                                             alcohol                                                                           % kind                                                                             %   °C.                                                                       bar                                                                              bar                                                                              bar                                                                              m.sup.3 /h                                                                       l/h                                                                              capacity                           __________________________________________________________________________     8   GR     EtOH                                                                              3.9                                                                             soy-                                                                             38.9                                                                              23 6  5  5.5                                                                              4.7                                                                              93 0.78                                9   6P         4.7                                                                             bean                                                                             18.7                                                                              26 3.4                                                                              2.5                                                                              2.9                                                                              4.7                                                                              51 0.06                               10   separation 3.4  4.0 26 2.6                                                                              1.6                                                                              2.1                                                                              5.5                                                                              199                                                                              0                                  11   limit      2.3  30.6                                                                              27 4.5                                                                              3.6                                                                              4.0                                                                              5.4                                                                              76 0.25                               12   of         3.6  30.7                                                                              23 6.2                                                                              5.4                                                                              5.8                                                                              4.6                                                                              110                                                                              0.62                               13   membranes: 2.7  34.6                                                                              25 5.7                                                                              4.8                                                                              5.2                                                                              4.8                                                                              72 0.41                               14   2500       2.6  36.4                                                                              26 5.7                                                                              4.8                                                                              5.2                                                                              4.8                                                                              85 0.44                               15              4.8  43.9                                                                              28 5.8                                                                              4.8                                                                              5.3                                                                              4.6                                                                              93 0.40                               16              3.5  43.6                                                                              30 4.6                                                                              3.5                                                                              4.0                                                                              5.0                                                                              80 0.76                               17          i-Pr--                                                                            3.5  33.9                                                                              24 5.2                                                                              3.8                                                                              4.5                                                                              4.2                                                                              76 0.29                               18          OH  2.8  38.7                                                                              24 3.8                                                                              2.2                                                                              3.0                                                                              4.4                                                                              51 0.56                               19          EtOH                                                                              8.4                                                                             egg                                                                              54.4                                                                              25 5.6                                                                              3.9                                                                              4.7                                                                              4.7                                                                              42 0.98                               20              8.9  48.3                                                                              24 5.4                                                                              3.8                                                                              4.6                                                                              4.6                                                                              97 0.98                               21   GR     EtOH                                                                              1.2                                                                             soy-                                                                             75.7                                                                              22 5.1                                                                              4.8                                                                              4.9                                                                              3.8                                                                              21 0.92                               22   8P         3.6                                                                             bean                                                                             55.7                                                                              29 7.9                                                                              7.6                                                                              7.7                                                                              3.0                                                                              17 0.86                                    TGM: 10000                                                               __________________________________________________________________________                                      data of products recovered,                                                   solution reduced                                                              on rotary evaporator, freeze dried                          lecithin con-             PC-                                 type of         centration                                                                            JZ    POZ H.sub.2 O                                                                             content                             Example                                                                            membrane                                                                             alcohol                                                                           R (%)                                                                             P (%)                                                                             R  P  R P R (%)                                                                             P (%)                                                                             R (%)                                                                             P (%)                           __________________________________________________________________________     8   GR     EtOH                                                                              4.6 1.1 92.6                                                                             75.4                                                9   6P         4.8 4.5 99.4                                                                             93.9                                               10   separation                                                                           3.4 3.4 3.4 94.7                                                                             94.7                                               11   limit      2.4 1.8 93.9                                                                             93.5                                               12   of         6.9 2.6 97.3                                                                             92.6                                               13   membranes: 2.9 1.7 93.9                                                                             88.0                                               14   2500       2.9 1.6 95.6                                                                             82.5                                               15              3.2 1.9 94.1                                                                             89.0                                               16              5.5 1.3 101.7                                                                            82.0                                               17          i-Pr--                                                                            4.1 2.9 97.0                                                                             93.0                                               18          OH  3.9 1.7 96.0                                                                             93.0                                               19          EtOH                                                                              28.5                                                                              0.5 74.0                                                                             30     1.07    79  10.9                            20              16.3                                                                              0.4 71.2                                                  21   GR     EtOH                                                                              1.8 0.1 99.8                                                                             51.2                                                                             3.8         70  20                              22   8P         3.7 0.5 90.1                                                                             53.3                                                    TGM: 10000                                                               __________________________________________________________________________     T = test temperature;                                                         P. in = module inlet pressure;                                                P. out = module outlet pressure;                                              KFl = concentrate flow;                                                       PFl = permeate flow;                                                          JZ = iodine number;                                                           R = retent;                                                                   P = permeating substance;                                                     PC = phosphatidylcholine;                                                     TGM = separation limit of membranes                                      

Numerous formulations exist for a lipid emulsion suitable foradministration to human beings via the intravenous route. Virtually allsuch formulations have embodied three basic components: (1) an aqueousphase, (2) an emulsifying (stabilizing) system and (3) a lipid phase.Components and concentrations of compositions of commercially availablelipid emulsions are given at page 15, Table I of the Thompson bookreferred to above.

This invention is directed to only that part of the intraveneouscomposition identified as the lecithin, the emulsifier system. Theremaining constituents of the intraveneous composition (lipid phase,e.g., soya oil, and aqueous phase, e.g., glycerine, and distilled water)are conventional. Typical percentages and concentrations for using thepresent invention are disclosed in the Thompson book.

Specific examples of two recipes for a composition suitable foradministration by intraveneous injection are as follows:

    ______________________________________                                                       10% fat                                                                              20% fat                                                 ______________________________________                                        soya oil refined 10.0%    20.0%                                               glycerine DAB 7  5.0%     5.0%                                                lecithin         1.2%     2.0%                                                distilled water  83.8%    73.0%                                               ______________________________________                                    

An emulsion for intraveneous administration is prepared as follows. Stir12 g of lecithin, prepared according to the present invention, in 838 gdistilled water of approximately 50° C. until finely dispersed. Heat 50g glycerine and 100 g soya oil refined to 50° C. each. First add theglycerine by stirring to the lecithin-water dispersion; then add thesoya oil refined by intensive stirring. Homogenize the mixtureimmediately. Decant the emulsion and sterilize. An alternative emulsionfor intraveneous administration may use 20 g lecithin prepared accordingto the present invention; 50 g glycerine; 730 g distilled water and 200g soya oil refined. The procedure for the preparation of both emulsionsis the same.

Various modifications in structure and/or function, process steps and/orconstituents may be made by one skilled in the art without departingfrom the scope of the invention as defined by the claims.

What is claimed is:
 1. A method of intravenous treatment comprising theintravenous administration to a host of an emulsion from lecithin basehaving the following physico-chemical parameters:(1) ratio between Pcand Pe from 7:3 to 6:1, preferably 4:1, (2) Pc content from 65 to 85% byweight, preferably from 75 to 80% by weight, (3) residual fat contentless than 2%, (4) pyrogen-free in the rabbit test according to theEuropean Pharmacopoeia (1975), vol. 2, page 56 et seq., (5) clearlysoluble in ethanol at 5% concentration, (6) clearly soluble inchloroform at 10% concentration, (7) maximum water content 2.5%,preferred maximum 1%, (8) maximum peroxide number 5, preferred maximum 1(determined according to the DGF standard method F-1 3b (68).
 2. Methodof providing lecithin intravenously into the human body comprising thesteps of:(a) preparing a distilled water lecithin dispersion by treatinga phospholipid mixture which contains phosphatidylcholine (Pc) andphosphatidylethanolamine (Pe) dissolved in alcohol with sufficient waterto cause the partial precipitation of undissolved components of thephospholipid mixture; (b) heating glycerine and refined soya oilseparately; (c) adding the heated glycerine to the lecithin waterdispersion; (d) adding the soya oil by intense stirring; (e)homogenizing the resulting mixture; (f) decanting the emulsion; (g) andthen sterilizing and administering intravenously.
 3. Method of claim 2,wherein the lecithin dispersion is 1-2% of the total mixture.
 4. Methodof claim 2, wherein the refined soya oil added is between 10 and 20%.